Systems and methods for home position and cart acquisition with a materials handling vehicle

ABSTRACT

A variety of vehicle-based and warehouse-based solutions are provided to increase the adaptability, utility, and efficiency of materials handling vehicles in the warehouse environment, such as a goods storage and retrieval system, comprising a multilevel warehouse racking system, a mobile storage cart, a cart home position, and a materials handling vehicle disposed on a vehicle transit surface and comprising a fork carriage assembly, a navigation subsystem, a cart engagement subsystem, and one or more vehicular controllers to use the navigation subsystem to navigate the materials handling vehicle along the vehicle transit surface to a localized engagement position where the cart home position is within a cart engagement field of view, and use the cart engagement subsystem to engage the mobile storage cart in the cart home position with the fork carriage assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.Nos. 62/340,071 and 62/340,513, both filed May 23, 2016, andincorporated by reference in their entireties herein. This applicationis related, but does not claim priority, to U.S. patent application Ser.No. 15/602,738, filed May 23, 2017, and Ser. No. 15/602,752, filed May23, 2017, and International PCT Patent Application Serial No.PCT/US2017/034026, filed May 23, 2017.

BACKGROUND

The present disclosure relates to materials handling vehicles andwarehousing solutions related thereto.

BRIEF SUMMARY

According to the subject matter of the present disclosure, a variety ofvehicle-based and warehouse-based solutions are provided to increase theadaptability, utility, and efficiency of materials handling vehicles inthe warehouse environment.

In accordance with one embodiment of the present disclosure, a goodsstorage and retrieval system comprises a multilevel warehouse rackingsystem, a mobile storage cart, a cart home position, and a materialshandling vehicle disposed on a vehicle transit surface. The materialshandling vehicle comprises a vehicle body, a plurality of wheelssupporting the vehicle body, a traction control unit, a braking system,and a steering assembly, each operatively coupled to one or more of thevehicle wheels, a mast assembly, a fork carriage assembly movablycoupled to the mast assembly, a mast assembly control unit, a carriagecontrol unit, a picking attachment secured to the fork carriageassembly, a cart engagement subsystem, a navigation subsystem, and oneor more vehicular controllers. The one or more vehicular controllers arein communication with the traction control unit, the braking system, thesteering assembly, the mast assembly control unit, the carriage controlunit, the picking attachment, the cart engagement subsystem, and thenavigation subsystem. The cart engagement subsystem is characterized bya cart engagement field of view. The one or more vehicular controllersof the materials handling vehicle executes vehicle functions to: (i) usethe navigation subsystem to navigate the materials handling vehiclealong the vehicle transit surface to a localized engagement positionwhere the cart home position is within the cart engagement field ofview; and (ii) use the cart engagement subsystem to engage the mobilestorage cart in the cart home position with the fork carriage assembly.

In accordance with another embodiment of the present disclosure, a goodsstorage and retrieval system comprises a multilevel warehouse rackingsystem, a mobile storage cart, a cart home position, and a materialshandling vehicle disposed on a vehicle transit surface. The materialshandling vehicle comprises a vehicle body, a fork carriage assembly, acarriage control unit, a picking attachment secured to the fork carriageassembly, a cart engagement subsystem, a navigation subsystem, and oneor more vehicular controllers in communication with the carriage controlunit, the picking attachment, the cart engagement subsystem, and thenavigation subsystem. The cart engagement subsystem is characterized bya cart engagement field of view. The one or more vehicular controllersof the materials handling vehicle executes vehicle functions to: (i) usethe navigation subsystem to navigate the materials handling vehiclealong the vehicle transit surface to a localized engagement positionwhere the cart home position is within the cart engagement field ofview; and (ii) use the cart engagement subsystem to engage the mobilestorage cart in the cart home position with the fork carriage assembly.

In accordance with yet another embodiment of the present disclosure, amaterials handling vehicle configured to navigate a vehicle transitsurface comprises a vehicle body, a plurality of wheels supporting thevehicle body, a traction control unit, a braking system, and a steeringassembly, each operatively coupled to one or more of the vehicle wheels,a mast assembly, a fork carriage assembly movably coupled to the mastassembly, a mast assembly control unit, a carriage control unit, apicking attachment secured to the fork carriage assembly, a cartengagement subsystem, a navigation subsystem, and one or more vehicularcontrollers in communication with the traction control unit, the brakingsystem, the steering assembly, the mast assembly control unit, thecarriage control unit, the picking attachment, the cart engagementsubsystem, and the navigation subsystem. The cart engagement subsystemis characterized by a cart engagement field of view. The one or morevehicular controllers of the materials handling vehicle executes vehiclefunctions to: (i) use the navigation subsystem to navigate the materialshandling vehicle along the vehicle transit surface to a localizedengagement position where a cart home position is within the cartengagement field of view; and (ii) use the cart engagement subsystem toengage a mobile storage cart in the cart home position with the forkcarriage assembly.

In accordance with yet one other embodiment of the present disclosure, amethod of operating a goods storage and retrieval system comprisesproviding the goods storage and retrieval system comprising a multilevelwarehouse racking system, a mobile storage cart, a cart home position,and a materials handling vehicle disposed on a vehicle transit surface.The materials handling vehicle comprises a vehicle body, a plurality ofwheels supporting the vehicle body, a traction control unit, a brakingsystem, and a steering assembly, each operatively coupled to one or moreof the vehicle wheels, a mast assembly, a fork carriage assembly movablycoupled to the mast assembly, a mast assembly control unit, a carriagecontrol unit, a picking attachment secured to the fork carriageassembly, a cart engagement subsystem, a navigation subsystem, and oneor more vehicular controllers in communication with the traction controlunit, the braking system, the steering assembly, the mast assemblycontrol unit, the carriage control unit, the picking attachment, thecart engagement subsystem, and the navigation subsystem. The cartengagement subsystem is characterized by a cart engagement field ofview. The method further comprises navigating the materials handlingvehicle along the vehicle transit surface to a localized engagementposition where the cart home position is within the cart engagementfield of view through use of the navigation subsystem and the one ormore vehicular controllers, and engaging the mobile storage cart in thecart home position with the fork carriage assembly through use of thecart engagement subsystem.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description of specific embodiments of thepresent disclosure can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 illustrates a goods storage and retrieval system including amultilevel warehouse racking system, mobile storage carts, a cart homeposition, and a plurality of materials handling vehicles according tovarious embodiments shown and described herein;

FIG. 2 illustrates a materials handling vehicle including, inter alia, adrive unit case housing a removable hand-held drive unit, a mobilestorage cart with an anti-rock cart engagement mechanism and mobilestorage cart support platform, and a picking attachment in position toengage a target tote according to various embodiments shown anddescribed herein;

FIG. 3 illustrates the picking attachment of FIG. 2;

FIG. 4 illustrates the picking attachment and the materials handlingvehicle of FIG. 2 in a position in which a slide-out of the pickingattachment are in an extended position to either retrieve the targettote from, or store the target tote on, a shelf insert;

FIG. 5 illustrates the materials handling vehicle of FIG. 2 in aposition in which the slide-out have positioned the target tote in thepicking attachment in a secured position;

FIG. 6 illustrates the picking attachment and the materials handlingvehicle of FIG. 2 in a position in which the picking attachment is inrotational alignment with a shelf of the engaged mobile storage cart andthe slide-out are in an extended position to either retrieve the targettote from or store the target tote on the shelf;

FIG. 7 illustrates a rack of the multilevel warehouse racking system ofFIG. 1 in which the rack supports a shelf insert on a bottom shelf,which shelf insert stores a plurality of totes, according to variousembodiments shown and described herein;

FIG. 8 illustrates the shelf insert of FIG. 7 without the plurality oftotes;

FIG. 9 illustrates an exploded view of the shelf insert of FIG. 8;

FIG. 10 is a schematic illustration of various controllers of thematerials handling vehicle in communication with a hand-held drive unitand vehicle subsystems according to various embodiments shown anddescribed herein;

FIG. 11 illustrates the drive unit case of FIG. 2 in an open position toshow the removable hand-held drive unit;

FIG. 12 is a schematic illustration of a computing device according tovarious embodiments shown and described herein;

FIG. 13 is a flow chart illustrating cart acquisition methodologyaccording to various embodiments shown and described herein;

FIG. 14 is a flow chart illustrating tote engagement methodologyaccording to various embodiments shown and described herein;

FIG. 15 illustrates another materials handling vehicle according tovarious embodiments shown and described herein;

FIG. 16 illustrates a goods-to-man warehousing system with a pickstation configuration according to various embodiments shown anddescribed herein;

FIG. 17 illustrates a goods-to-man warehousing system with another pickconfiguration according to various embodiments shown and describedherein; and

FIG. 18 illustrates a process for integration and utilization with thegoods-to-man warehousing system of FIG. 16 and/or FIG. 17.

DETAILED DESCRIPTION

Referring initially to FIG. 1, a goods storage and retrieval systemcomprises a multilevel warehouse racking system 12, a mobile storagecart 14, a cart home position 16, and a materials handling vehicle 102disposed on a vehicle transit surface 106. Referring to FIGS. 1 and 10,the materials handling vehicle 102 comprises a vehicle body 104, aplurality of wheels 210 supporting the vehicle body 104, a tractioncontrol unit 606, a braking system 604, and a steering assembly 608,each operatively coupled to one or more of the vehicle wheels 210. Thematerials handling vehicle 102 further comprises a mast assembly 207, afork carriage assembly 206 movably coupled to the mast assembly 207, amast assembly control unit 610, a carriage control unit 611, a pickingattachment 602 secured to the fork carriage assembly 206, a cartengagement subsystem 18, a navigation subsystem 20, and one or morevehicular controllers in communication with the traction control unit606, the braking system 604, the steering assembly 608, the mastassembly control unit 610, the carriage control unit 611, the pickingattachment 602, the cart engagement subsystem 18, and the navigationsubsystem 20.

While the mast assembly 207 is depicted in FIG. 1 as extending overthree times a height of the vehicle body 104, it is understood andwithin the scope of this disclosure that the mast assembly 207 mayextend to different heights with respect to the vehicle body 104. Forexample, the mast assembly may be extend to about one to one-and-a-halftimes the height of the vehicle body 104. In addition, alternativeembodiments of a materials handling vehicle as describe herein arepossible and within the scope of this disclosure, such as a materialshandling vehicle 102′ depicted in FIG. 15 including an alternative forkcarriage assembly 206′ and post 76′ to which the picking attachment 602,described in greater detail further below, may be attached and operatedas described herein. The aforementioned materials handling vehicles mayinclude lift trucks available from Crown Equipment Corporation such as,for example, SP Series Order Pickers such as the Crown SP 3500/4500Series Order Picker and/or TSP Turret Trucks such as one of the TSP 7000VNA Truck Series as depicted in FIG. 15. The materials handling vehiclesmay incorporate automated guidance vehicle (“AGV”) functionality using,for example, wire guidance or other guidance features for AGVpositioning system functionality.

The cart engagement subsystem 18, which is illustrated schematically inFIG. 10, is characterized by a cart engagement field of view 22, whichmay be defined by a vision system 40 within the cart engagementsubsystem 18. The vehicular controller(s) of the materials handlingvehicle 102 execute vehicle functions to: (i) use the navigationsubsystem 20 to navigate the materials handling vehicle 102 along thevehicle transit surface 106 to a localized engagement position where thecart home position 16 is within the cart engagement field of view 22,and (ii) use the cart engagement subsystem 18 to engage the mobilestorage cart 14 in the cart home position 16 with the fork carriageassembly 206.

More specifically, the cart engagement subsystem 18 may be operativelycoupled to at least one of the traction control unit 606, the brakingsystem 604, the steering assembly 608, the mast assembly control unit610, the carriage control unit 611, and the picking attachment 602 tofacilitate cart engagement. The cart engagement subsystem 18 may becoupled to these components directly, or indirectly, through thevehicular controller(s). The cart engagement subsystem 18 may be furthercharacterized by a close approach field of view 24 that is morerestricted than the cart engagement field of view 22 defined by thevision system 40. The cart engagement subsystem 18 may transition froman initial approach mode in the cart engagement field of view 22 to aclose approach mode in the close approach field of view 24 as the carthome position 16 moves into the close approach field of view 24.

In embodiments, the cart engagement subsystem 18 may comprise atime-of-flight (TOF) system 26 characterized by the close approach fieldof view 24 and the close approach mode may rely primarily on the TOFsystem 26 when the cart home position 16 moves into the close approachfield of view 24. The cart engagement subsystem 18 is configured togenerate a target TOF depth map of the mobile storage cart 14. Further,the vehicular controller(s) of the materials handling vehicle 102 mayexecute vehicle functions to (i) use the cart engagement subsystem 18 togenerate the target TOF depth map of the mobile storage cart 14 in thecart home position 16, and (ii) use the cart engagement subsystem 18 todetermine a range position of the mobile storage cart 14 with respect tothe cart engagement subsystem 18 based on the target TOF depth map.

In embodiments, the close approach field of view 24 defined by the TOFsystem 26 is more restricted than the cart engagement field of view 22defined by the vision system 40. and the cart engagement subsystem 18may transition from cart engagement operations that rely primarily onthe vision system 40 to cart engagement operations that rely primarilyon the TOF system 26 as the cart home position 16 moves into the closeapproach field of view 24.

The navigation subsystem 20 may comprise one or more environmentalsensors and an environmental database. In embodiments, the environmentalsensors are configured to capture data indicative of a position of thematerials handling vehicle 102 relative to the multilevel warehouseracking system 12, the vehicle transit surface 106, or both. Further,the environmental database may comprise stored data indicative of themultilevel warehouse racking system 12, the vehicle transit surface 106,or both. The navigation subsystem 20 may be configured to enable atleast partially automated navigation of the materials handling vehicle102 along the vehicle transit surface 106 utilizing the captured dataand the stored data. For example, and not by way of limitation, it iscontemplated that the navigation subsystem 20 may utilize a storedwarehouse map and captured images of ceiling lights or sky lights toenable navigation, as is disclosed in U.S. Pat. No. 9,174,830 issued onNov. 3, 2015, U.S. Pat. No. 9,340,399 issued on May 17, 2016, and othersimilar patents and patent publications. Additional suitableenvironmental sensors include, but are not limited to, inertial sensors,lasers, antennae for reading RFID tags, buried wires, WiFi signals, orradio signals, global positioning system (GPS) sensors, globalnavigation satellite system (GNSS) sensors, or combinations thereof.

In embodiments, a warehouse map 30 is stored in a memory that iscommunicatively coupled to the vehicular controller(s). The vehicularcontroller(s) of the materials handling vehicle 102 may execute vehiclefunctions to use the navigation subsystem 20 to determine a localizedposition of the materials handling vehicle 102 with respect to thevehicle transit surface 106 of a warehouse 11 based on a position of thematerials handling vehicle 102 in the warehouse 11 in comparison withthe warehouse map 30. The vehicular controller(s) of the materialshandling vehicle 102 may further execute vehicle functions to use thenavigation subsystem 20 to track navigation of the materials handlingvehicle 102 along the vehicle transit surface 106 based on the localizedposition, navigate the materials handling vehicle 102 along the vehicletransit surface 106 in at least a partially automated manner, or both.

The navigation subsystem 20 may be operatively coupled to at least oneof the traction control unit 606, the braking system 604, the steeringassembly 608, the mast assembly control unit 610, the carriage controlunit 611, and the picking attachment 602 to facilitate cart engagement.Further, the navigation subsystem 20 may be coupled to these componentsdirectly, or indirectly, through the vehicular controller(s).

Referring further to FIG. 2, the picking attachment 602 may comprise anX-Y-Z-Ψ positioner 60 and the vehicular controller(s) of the materialshandling vehicle 102 may execute vehicle functions to use the X-Y-Z-Ψpositioner 60 of the picking attachment 602 to engage and disengage atarget tote 50 positioned in the multilevel warehouse racking system 12with the picking attachment 602.

As illustrated in FIG. 3, the X-Y-Z-Ψ positioner 60 may comprise anX-positioner 64 configured to move the picking attachment in a firstdegree of freedom along a first lateral axis 65 in a lateral plane, aY-positioner 66 configured to move the picking attachment in a seconddegree of freedom along a second lateral axis 67 perpendicular to thefirst lateral axis 65 in the lateral plane, a Z-positioner 68 configuredto move the picking attachment in a third degree of freedom along aZ-axis 69 perpendicular to the first lateral axis 65 and the secondlateral axis 67, and a rotational Ψ-positioner 70 configured to rotatethe picking attachment 602 in a fourth degree of freedom about theZ-axis 69. The X-positioner 64 may comprise rails 72 configured topermit movement of the picking attachment 602 along the first lateralaxis 65. The Y-positioner 66 may comprise rails 74 configured to permitmovement of the picking attachment 602 along the second lateral axis 67.The Z-positioner 68 may comprise a vertical displacement mechanismconfigured to slidably engage with a post 76 of the fork carriageassembly 206 for vertical displacement with respect to the fork carriageassembly 206. The rotational Ψ-positioner 70 may comprise a shaft 78configured to permit rotation of the picking attachment 602 about theZ-axis 69. Such “rails” may include mechanical engagement componentssuch as one or more tracks fixed on an upright support, each includingan engagement mechanism configured to engage with a correspondingengagement mechanism of a respective positioner for a slidingengagement. For example, an engagement mechanism of a rail may be one ofa notch or a protrusion configured to slidably engage with the notch,and the corresponding engagement mechanism may be the other of the notchor the protrusion. As a non-limiting example, the tracks may be barsmade of metal such as stainless steel or a like suitable materialunderstood to be within the scope of this disclosure.

The materials handling vehicle 102 may further comprises a pickingattachment subsystem 62, which is illustrated schematically in FIG. 10,in communication with the vehicular controller(s) of the materialshandling vehicle 102. As is illustrated in FIG. 3, the pickingattachment subsystem 62 may comprises the picking attachment 602(including the X-Y-Z-Ψ positioner 60) and the time-of-flight (TOF)system 26. The picking attachment subsystem 62 is configured to use theTOF system 26 to generate a target TOF depth map of the target tote 50.The vehicular controller(s) of the materials handling vehicle 102 mayexecute vehicle functions to use the X-Y-Z-Ψ positioner 60 of thepicking attachment subsystem 62 to engage the target tote 50 with thepicking attachment 602 based on the target TOF depth map. For example,the picking attachment 602 engages the target tote 50 or a target palletwith the aid of a TOF depth map, which is particularly useful forrotational (Ψ) positioning about the Z axis. Rotational adjustments maycompensate for target tote rotation or rotational error in the materialshandling vehicle 102. The navigation subsystem 20 may be configured toposition the materials handling vehicle 102 such that the target tote 50is within a tote engagement field of view 52 of the TOF system 26.

The vision system 40 may also be part of the navigation subsystem 20,and the multilevel warehouse racking system 12 may comprises a targetfiducial associated with the target tote 50. The navigation subsystem 20may be configured to position the materials handling vehicle 102 suchthat the target fiducial is within a field of view of the vision system40. The navigation subsystem 20 may further be configured to utilize thetarget fiducial to position the materials handling vehicle 102 such thatthe target tote 50 is within the tote engagement field 52 of view of theTOF system 26. For example, it is contemplated that suitable targetfiducials may include markings or tags on the warehouse racking system,or distinctive elements of the racking system itself. An example isdepicted in FIG. 4 with respect to a target fiducial 32 disposed on arack module such as a shelf unit. Rack modules within the scope of thisdisclosure may have different numbers of slots to position items such astotes within, and a fiducial such as the target fiducial 32 attached toeach rack module may be configured to identify the number of slots perrespective module. Once a position of the target fiducial 32 is recordedas an X-Y-Z position on the warehouse map 30, a position of the totes(including, for example, the target tote 50) within the shelf unit willbe known as well. The same location may be utilized to pick objects suchas a pallets through a materials handling vehicle (such as the materialshandling vehicle 102′ of FIG. 15) at another time or for manual stockpicking. An entire rack module including or empty of one or more totes49 may be picked as described herein from a storage location such as theshelf unit or a target tote 50 may be individually picked as describedherein. A target tote 50 to be picked may not include a target fiducialbut may be stored in a storage location such as a shelf unit of FIG. 4that includes the target fiducial 32 to guide the materials handlingvehicle 102 to the localized position of the shelf unit to engage thetarget tote 50 as described herein. Alternatively, both the rackingmodule, such as the shelf unit, and the target tote 50 may includetarget fiducials to guide engagement of the target tote 50 with thepicking attachment 602 as described herein.

With reference to FIGS. 4-6, a picking scheme as described herein mayinclude travel to a tote location 54 of a target tote 50 within a rackmodule 34 to engage the target tote 50. Another picking scheme mayinclude travel to a rack module 34 within a rack bay 38 of themultilevel warehouse racking system 12 and visualization of a targetfiducial 32 of the rack module 34 to pick, based on, for example, knowncoordinates of the target fiducial 32, the entire rack module 34 or atarget tote 50 from within the rack module 34. Further, a picking schememay include dual target fiducial visualization and include travel to arack module 34 within a rack bay 38 of the multilevel warehouse rackingsystem 12, visualization of a target fiducial 32 of the rack module 34,movement to a location of a target tote 50 within the visualized rackmodule 34 based on information received from visualization of that rackmodule 34, visualization of the target tote 50 within the rack module34, and engagement of the target tote 50 by the picking attachment 602as described herein. Thus, the navigation subsystem 20 may be configuredto position the materials handling vehicle 102 such that the targetfiducial 32 of a shelf unit 36 of the rack module 34 FIG. 4 is within afield of view of the vision system 40. The navigation subsystem 20 mayadditionally be configured to utilize the target fiducial 32 to positionthe materials handling vehicle 102 such that the shelf unit 36 is withina rack module field of view of the TOF system 26. The navigationsubsystem may further be configured to utilize a target fiducial of thetarget tote 50 within the rack module field of view to position thematerials handling vehicle 102 such that the target tote 50 is withinthe tote engagement field 52 of view of the TOF system 26.

As illustrated in FIGS. 4 and 5, the target tote 50 may be stored withina rack module 34 such as on a shelf unit 36 of the multilevel warehouseracking system 12. The shelf unit 36 may alternatively be a shelf insert404 as illustrated in FIG. 7, and which is described in greater detailfurther below. In FIG. 4, the picking attachment 602 of the materialshandling vehicle 102 of FIG. 2 is in a position in which a slide-out 90of the picking attachment 602 are in an extended position to eitherretrieve the target tote 50 from or store the target tote 50 on theshelf unit 36. In FIG. 5, the materials handling vehicle 102 of FIG. 2is in a position in which the slide-out 90 has positioned the targettote 50 in the picking attachment 602 in a secured position. In FIG. 6,the materials handling vehicle 102 of FIG. 2 is in a position in whichthe picking attachment 602 is in rotational alignment, through arotation as described in greater detail below, with a shelf of theengaged mobile storage cart 14, and the slide-out 90 is in an extendedposition to either retrieve the target tote 50 from or store the targettote 50 on the shelf of the engaged mobile storage cart 14.

A method 800 of operating the goods storage and retrieval system 10according to one embodiment of the present disclosure is illustrated inFIG. 13 and may be read in light of the system components of FIGS. 1 and10. As illustrated in FIG. 13, the method 800 includes a step 802 tostart cart acquisition followed by a step 804 to receive informationregarding a localized engagement position of the cart home position 16.The method further includes in step 806, and through use of thenavigation subsystem 20 and the vehicular controller(s), navigating thematerials handling vehicle 102 along the vehicle transit surface 106 toa localized engagement position and receiving information from the cartengagement field of view in step 808. If in step 810 the cart homeposition 16 is not within the cart engagement field of view 22, themethod 800 returns to step 806. Otherwise, if in step 810 the cart homeposition 16 is within the cart engagement field of view 22, the method800 continues on to step 810 and uses the cart engagement subsystem 18to engage the mobile storage cart 14 by engaging the mobile storage cart14 in the cart home position 16 with the fork carriage assembly 206.

In embodiments, a method 820 of operating the goods storage andretrieval system 10 may include, as illustrated in FIG. 14, a step 822to start tote engagement followed by a step 824 to receive informationregarding a target tote position of a target tote 50. The method 820further includes, in step 826, and through use of at least one of thenavigation subsystem 20, the picking attachment subsystem 62, and thevehicular controller(s), navigation the materials handling vehicle 102toward the target tote position and aligning the picking attachment 602with the target tote 50. In step 828, information is received from thetote engagement field of view 52. If in step 830 the target toteposition is not within the tote engagement field of view 52, the method820 returns to step 826. Otherwise, if in step 830 the target toteposition is within the tote engagement field of view 52, the method 820continues on to step 832 to generate a target tote depth map and, instep 834, to use the picking attachment subsystem 62 to the engage thetarget tote 50 based on the target tote depth map.

With either or a combination of the methods 800 or 820, a velocitynumber may be assigned to a stock keeping unit (SKU) associated with atarget tote 50 in the multilevel warehouse racking system 12 based on anorder velocity indicative of a frequency of usage parameter associatedwith the target tote 50. A relatively high velocity number may beassociated with a low storage position on a low shelf of the multilevelwarehouse racking system 12, and a relatively low velocity number may beassociated with a high storage position on a high shelf of themultilevel warehouse racking system 12. For example, a lowest velocitynumber may be associated with a highest shelf, and a highest velocitynumber may be associated with a lowest shelf.

Further, the picking attachment 602 and the fork carriage assembly 206may be used to move the target tote 50 from a portion of the multilevelwarehouse racking system 12 associated with a relatively low velocitynumber to a portion of the multilevel warehouse racking system 12associated with a relatively high velocity number based on an increasein the order velocity with respect to the target tote 50. Further, thepicking attachment 602 and the fork carriage assembly 206 may be used tomove the target tote 50 from a portion of the multilevel warehouseracking system 12 associated with a relatively high velocity number to aportion of the multilevel warehouse racking system 12 associated with arelatively low velocity number based on a decrease in the order velocitywith respect to the target tote 50.

In embodiments, a first target tote may be engaged at a first storageposition on a high shelf associated with a relatively low velocitynumber with the picking attachment 602. The first target tote may beplaced with the picking attachment 602 in the mobile storage cart 14engaged by the fork carriage assembly 206. Further, the materialshandling vehicle 102 may be navigated to a second target tote when thesecond target tote is assigned a relatively high velocity number and iswithin a close distance to the first storage position. The second targettote may be engaged with the picking attachment 602, which may lower thesecond target tote to a low shelf associated with the relatively highvelocity number or place the second target tote in the mobile storagecart 14. For example, the materials handling vehicle 102 may benavigated to a subsequent pick location when the second target tote isplaced in the mobile storage cart 14, and the second target tote may beplaced on the low shelf associated with the relatively high velocitynumber while at the subsequent pick location.

In other embodiments, a first target tote may be engaged at a storagefirst position on a low shelf associated with the high velocity numberwith the picking attachment 602, and the picking attachment 602 mayplace the first target tote in the mobile storage cart 14 engaged by thefork carriage assembly 206. Further, the materials handling vehicle 102may be navigated to a second target tote when the second target tote isassigned a relatively low velocity number and is within a close distanceto the first position on the low shelf to engage the second target totewith the picking attachment 602 and either raise the second target toteto a high shelf associated with the relatively low velocity number orplace the second target tote in the mobile storage cart 14. For example,the materials handling vehicle 102 may be navigated to a subsequent picklocation when the second target tote is placed in the mobile storagecart 14, and the picking attachment 602 places the second target tote onthe high shelf associated with the relatively low velocity number whileat the subsequent pick location.

In embodiments, positioning the materials handling vehicle 102 may bepositioned in a first aisle of the multilevel warehouse racking system12, and one or more target totes 50 may be placed with the pickingattachment 602 in the mobile storage cart 14 engaged by the forkcarriage assembly 206. Further, the mobile storage cart 14 may be usedas a temporary storage location to level inventory when one or moreinventory orders are received such that the one or more target totes 50are shuffled between the mobile storage cart 14 and a plurality ofshelves of the multilevel warehouse racking system 12 based on arespective order velocity indicative of a frequency of usage parameterassociated with each target tote 50 to optimize a usage parameter withrespect to the first aisle. Advantages from such inventory leveling mayinclude fewer trips by the materials handling vehicle 102 back and forththrough an aisle and more picks and puts per distance traveled by thepicking attachment 602 of the materials handling vehicle 102 to lower acost per pick. It is contemplated that such an inventory leveling systemmay work in conjunction with a warehouse management system to controlproduct flow and optimize pick and replenishment and to organizeproducts based on an average or known velocity based on product demand.

With such an inventory leveling system, a relatively low velocity numberassociated with a high shelf of the multilevel warehouse racking system12 may be assigned to a SKU associated with a first target tote that isstored in the mobile storage cart 14, and a relatively high velocitynumber associated with a low shelf of the multilevel warehouse rackingsystem 12 may be assigned to a SKU associated with a second target totestored on a high shelf of the multilevel warehouse racking system 12.Information may be received indicative of the second target tote beingstored on the high shelf. The materials handling vehicle 102 may benavigated to a location of the multilevel warehouse racking system 12associated with the high shelf during an off-peak picking time or an offshift time, and the mobile storage cart 14 engaged by the fork carriageassembly 206 may be moved to the high shelf. Once in position, thepicking attachment 602 may exchange the first target tote stored in themobile storage cart 14 with the second target tote stored on the highshelf to store the second target tote in the mobile storage cart 14.Such an exchange is to level inventory and reduce the amount of forkcarriage assembly raising and lowering needed to retrieve target totes50. This would be particularly significant during, for example, peakperiods or high volume shifts because it would reduce the time needed tofulfill an inventory order and the energy expended by the materialshandling vehicle 102.

In embodiments, one or more target totes 50 may be placed with thepicking attachment 602 in the mobile storage cart 14 engaged by the forkcarriage assembly 206 such that the mobile storage cart 14 is utilizedas a temporary storage location. The picking attachment pick and placeoperations may be interleaved by picking up and placing away multipletarget totes 50 during a single trip of the materials handling vehicle102 down an aisle of the multilevel warehouse racking system 12.

The first aisle may comprise a very narrow aisle (VNA). Further, use ofthe mobile storage cart 14 as a temporary storage location allows formultiple picks to be made in the aisle or while the fork carriageassembly 206 is raised to a high storage location to minimize energyused to raise and lower the fork carriage assembly 206. The mobilestorage cart 14 may also be used to fill multiple inventory order in abatch and deliver the entire batch to a location or to a transfer nodefor delivery to another location.

A first target tote may be stored on a shelf of a plurality of shelvesin the first aisle of the multilevel warehouse racking system 12, and asecond target tote may be stored in the mobile storage cart 14. Thefirst target tote on the shelf in a shelf location may be engaged by thepicking attachment 602 to pick up the first target tote with the pickingattachment 602, which may remove the first target tote from the shelflocation and place the first target tote on a shelf of the mobilestorage cart 14. The picking attachment 602 may engage the second targettote stored in the mobile storage cart 14, remove the second target totefrom the mobile storage cart 14, and place the second target tote in theshelf location to place away the second target tote.

The picking attachment 602 may be added as a vehicle retrofit such thatthe picking attachment 602 and materials handling vehicle 102collectively define dual axis vertical displacement. More specifically,as a non-limiting example, the mast assembly 207 and the mast assemblycontrol unit 610 may be configured to move the fork carriage assembly206 along a vertical axis Z′, and the picking attachment 602, whichcomprises the X-Y-Z-Ψ positioner 60, may be secured to the fork carriageassembly 206. The vehicular controller(s) of the materials handlingvehicle 102 executes vehicle functions to use the X-Y-Z-Ψ positioner 60of the picking attachment 602 to engage and disengage a target tote 50positioned in the multilevel warehouse racking system 12 with thepicking attachment 602. The mast assembly 207, mast assembly controlunit 610, and the picking attachment 602 are collectively configuredsuch that movement of the picking attachment 602 along the Z-axis 69 bythe X-Y-Z-Ψ positioner 60 is independent of movement of the forkcarriage assembly 206 along the vertical axis Z′ by the mast assembly207 and mast assembly control unit 610. It is noted that “independent”movement means that the X-Y-Z-Ψ positioner 60 can effectuate verticaldisplacement without relying on movement of the fork carriage assembly206 along the vertical axis Z′.

In embodiments, the mast assembly 207, mast assembly control unit 610,and the picking attachment 602 are collectively configured such thatmovement of the picking attachment 602 along the Z-axis 69 by theX-Y-Z-Ψ positioner 60 is supplemented by movement of the fork carriageassembly 206 along the vertical axis Z′ by the mast assembly 207 andmast assembly control unit 610. “Supplemental” movement contemplatesthat, since the picking attachment 602 is secured to the fork carriageassembly 206, movement of the picking attachment 602 along the Z-axis 69by the X-Y-Z-Ψ positioner 60 can also result from movement of the forkcarriage assembly 206 (for example, with respect to the mast assembly207) along the vertical axis Z′.

Referring to FIGS. 3-6, the picking attachment 602 may comprise aslide-out 90 that is configured to extend and retract to engage thetarget tote 50. The slide-out 90, which may be a telescoping assembly,is provided with hardware that selectively engages the target tote topush and pull the target tote into, and out of, a warehouse shelf in asliding motion. For example, and not by way of limitation, the slide-out90 may be provided with pivoting engagement fingers that pivot into andout of a sliding path of a target tote for tote engagement. Theslide-out 90 may be configured to slide within slots 92 defined in apair of inner side walls 94 of the picking attachment 602. Inembodiments, the picking attachment 602 may comprise a mechanismconfigured to grip the target tote 50 such as, for example, at least oneof a claw, a gripper, one or more vacuum cups, electromagnetic coils, anarticulating arm, and the like, as described in U.S. Prov. App. No.62/340,513, which has previously been incorporated herein in itsentirety.

Referring again to FIG. 2, the fork carriage assembly 206 may comprise amobile storage cart support platform 80 defined by one or more cartlifting forks 82 and an anti-rock cart engagement mechanism 300. Thevehicular controller(s) may be in communication with the cart engagementsubsystem 18 and may execute vehicle functions to use the cartengagement subsystem 18 to engage a mobile storage cart 14 supported bythe cart lifting forks 82 with the one or more cart lifting forks 82 andthe anti-rock cart engagement mechanism 300 of the fork carriageassembly 206. The anti-rock cart engagement mechanism 300 may comprise apair of support arms 302 configured to engage a pair of support armengagement features 304 disposed at and extending from a top end 84 of amobile storage cart 14 supported by the cart lifting forks 82. Eachsupport arm 302 may include a hook 306 defining a notch 308 anddownwardly extending from a distal portion 310 of the support arm 302.Further, each support arm engagement feature 304 may include ahorizontal lip 312 and a vertical prong 314. The horizontal lip 312 isconfigured to be supported on the distal portion 310 of the support arm302, and the vertical prong 314 is configured to be received andsupported by the notch 308 in the hook 306. In embodiments, theanti-rock cart engagement mechanism 300 is configured to engage themobile storage cart 14. In another embodiment, the anti-rock cartengagement mechanism 300 is configured to engage the mobile storage cart14 supported by the cart lifting forks 82. By way of example and not asa limitation, the anti-rock cart engagement mechanism 300 is configuredto engage the mobile storage cart 14 supported by the cart lifting forks82 at a cart contact point that is vertically displaced from the mobilestorage cart support platform 80 by a distance approximating a height ofthe mobile storage cart 14. In another embodiment, the anti-rock cartengagement mechanism 300 may be configured to engage the mobile storagecart 14 supported by the cart lifting forks 82 at a pair of cart contactpoints that are vertically displaced from the mobile storage cartsupport platform 80 by a distance approximating a height of the mobilestorage cart 14.

In other embodiments, as illustrated in FIG. 1, fork tines 83 may beused instead of the cart lifting forks 82. The fork tines 83 areconfigured to engage with a mobile storage cart 14′ that has a slightlydifferent construction than the mobile storage cart 14. A pallet clamp,as known in the art, is used to releasably secure the mobile storagecart 14′ to the materials handling vehicle 102. For example, a top endof the mobile storage cart 14′ is open rather than closed as shown withrespect to the mobile storage cart 14. Further, sides of the shelvingfor the mobile storage cart 14′ are not configured to face the materialshandling vehicle 102 when engaged by the materials handling vehicle 102and may be covered by, for example, a wired grid or mesh insert, whilesides of the shelving for the mobile storage cart 14 are shown as open.It should be understood that different suitable variations of thesemobile storages carts to be engaged with either the cart lifting forks82 or the fork tines 83 are within the scope of this disclosure. Forexample, the mobile storage cart 14 may also include a wired grid,plexiglass, or mesh insert along sides of shelving not configured toface the materials handling vehicle 102 when engaged.

FIG. 7 illustrates an embodiment of a rack 400 of the multilevelwarehouse racking system 12 having a plurality of shelves having atleast a portion configured to support a shelf insert 404 configured tostore one or more totes 51. As a non-limiting example, the shelf insert404 may be configured to adjoin at least one of an upright rail 406 ofthe rack 400 and another shelf insert 404 positioned in the rack 400.Further, as illustrated in FIGS. 8-9, the shelf insert 404 may include apair of supports 408, one or more cross beams 410, a cross channel 412,and one or more shelves 414. The one or more shelves 414 may beconfigured to receive and hold at least one tote 51.

The one or more cross beams 410 may be configured to be placed betweenthe pair of supports 408 that may span between and be supported by twocross rails 409 of the rack 400. For example, an L-shaped notch 411 ofeach support 408 may be defined by include a top surface configured toabut a top portion a cross rail 409 and a side surface configured toabut a side portion of the cross rail 409. The cross channel 412 may beconfigured to be placed above the one or more cross beams 410 andbetween and connected to the pair of supports 408.

Each cross beam 410 may comprise a pair of end hooks 416 configured torespectively be received within and engaged by notches 418 within thepair of supports 408. Each cross beam 410 may further comprise one ormore notches 420 disposed along the cross beam 410. Each shelf 414 ofthe one or more shelves 414 may be configured to be supported by arespective cross beam 410, and each shelf 414 may include a supportstructure 422 configured to be received in the one or more notches 420along the respective cross beam 410. Fasteners such as nuts, screws,bolts, and the like for reception in respective apertures or othersuitable fastening means understood to be within the scope of thisdisclosure such as industrial Velcro, solder, and the like may fastenthe components of the shelf insert 404 described herein together, andsuch fasteners may fasten the shelf insert 404 to the upright rail 406and/or to another shelf insert 404. In embodiments, a flat support panel(not shown) may be positioned below end portions of each shelf 414 andmay extend between the pair of supports 408.

Referring to FIGS. 1 and 10-11, the vehicle body 104 of the materialshandling vehicle 102 may be described as comprising a fork side 202 anda power unit side 204, with the fork carriage assembly 206 positioned atthe fork side 202 of the vehicle body 104 and being movably coupled tothe mast assembly 207. The materials handling vehicle 102 may include asensor location on the fork side 202, the power unit side 204, or bothto facilitate autonomous or semi-autonomous vehicle travel. Thematerials handling vehicle 102 may also comprise an operator compartment211 that may also be movably coupled to the mast assembly 207. Thisoperator compartment 211 may be positioned between the fork carriageassembly 206 and the power unit side 204 of the vehicle body 104.

A remote controller may include a hand-held drive unit 600 is secured tothe vehicle body 104 and comprises a user interface 632 and anoperational command generator 633 that is responsive to the userinterface 632. In alternative embodiments, the hand-hand drive unit 600may be remote from and not secured to the vehicle body 104.

The operational command generator 633 may comprise any suitablecombination of conventional, or yet-to-be developed, circuitry andsoftware that enables the hand-held drive unit 600 to send operationalcommands generated in response to user input at the user interface tothe vehicular controller(s) to control operational functions of thetraction control unit 606, the braking system 604, the steering assembly608, the mast assembly 207 through the mast assembly control unit 610,the picking attachment 602, or combinations thereof. The hand-held driveunit 600 may be secured to the vehicle body 104 so as to be accessiblefor removal from the vehicle body 104 from the power unit side 204 ofthe vehicle body 104 by an operator sharing (such as positioned on) thevehicle transit surface 106 with the wheels 210 supporting the vehiclebody 104.

The vehicle body 104 may also comprise a pair of lateral sides 208extending between the fork side 202 and power unit side 204 of thevehicle body 104, with the lateral sides 208 defining a vehicle widthw₁. In narrow aisle environments, where when the materials handlingvehicle 102 is positioned in a warehouse aisle characterized by an aislewidth w₂, where w₂−w₁<W inches where W is in a range of from about 2inches to about 4 inches (and w₂>w₁), the hand-held drive unit 600 issecured to the vehicle body 104 so as to be accessible for removal bythe operator sharing the vehicle transit surface 106 with the materialshandling vehicle 102. The equation above is an example equation for amaximum gap value, and values set forth are not contemplated to alimitation. As a non-limiting example, the hand-held drive unit 600 maybe secured to a surface of the power unit side 204 of the vehicle body104 and may be configured to permit an operator to fully control thematerials handling vehicle 102 positioned in a first aisle without aneed for the operator to travel down an empty, adjoining aisle next tothe first aisle to get to the operator compartment 211 on the fork side202 of the materials handling vehicle 102. In other words, a retrofittedmaterial handling vehicle 102 may require manual intervention on thepart of an operator and, if the operator is located in the first aisleon the power unit side 204 opposite from the operator compartment 211and unable to fit between the vehicle body 104 and the first aisle, thehand-held drive unit 600 provides a way for the operator to manuallyintervene without the need to get to the operator compartment 111. It iscontemplated that all of the functionality of the hand-held drive unit600 described herein is duplicated with user controls in the operatorcompartment 211 such that the operator may control the materialshandling vehicle 102 as if the operator were within the operatorcompartment 211 without actually being in the operator compartment 211.

The vehicular controller(s) may comprise a picking controller 612, abraking controller 614, a traction controller 616, a steering controller618, a mast controller 620, or one or more integrated controllers, tocontrol operational functions of the picking attachment 602, the brakingsystem 604, traction control unit 606, the steering assembly 608, or themast assembly control unit 610. Where the vehicular controller comprisesa traction controller 616 configured to control operational functions ofthe traction control unit 606, the user interface 632 of the hand-helddrive unit 600 may comprise traction control operators 626. The tractioncontroller 616 may be responsive to operational commands generated withthe traction control operators 626 of the hand-held drive unit 600. Forexample, it is contemplated that the traction control operators 626, andother types of control operators described herein, can be implemented ina variety of ways, such as via virtual buttons provided on a touchscreen display 634, physical inputs 636 located on the hand-held driveunit 600 (such as buttons, joysticks, etc.), any of which may bededicated or customizable. It is contemplated, for example, that thephysical inputs 636 may be customized using configurable menu options,scrolling interfaces, or other on-screen options provided at the touchscreen display 634. It is also contemplated that the body of thehand-held drive unit 600 could be used as a control operator if the unitwere to be provided with one or more motion sensors, such as agyroscope, accelerometer, etc., to detect movement and/or rotation ofthe hand-held drive unit 600. In further contemplated embodiments,gesture tracking, gaze tracking, voice control, and other types ofindirect control operators may be used.

The vehicular controller(s) may also comprise a braking controller 614configured to control operational functions of the braking system 604.The user interface of the hand-held drive unit 600 may comprise brakingcontrol operators 624. The braking controller 614 may be responsive tooperational commands generated with the braking control operators 624 ofthe hand-held drive unit 600.

Similarly, the vehicular controller(s) may comprise a steeringcontroller 618 configured to control operational functions of thesteering assembly 608. In which case, the user interface 632 of thehand-held drive unit 600 would comprise steering control operators 628,and the steering controller 618 would be responsive to operationalcommands generated with the steering control operators 628.

The vehicular controller(s) may also comprise a mast controller 620configured to control operational functions of the mast assembly controlunit 610 that is configured to control the mast assembly 207. In whichcase, the user interface 632 of the hand-held drive unit 600 wouldcomprise mast assembly control operators 630, and the mast controller620 would be responsive to operational commands generated with the mastassembly control operators 630.

The vehicular controller(s) may additionally comprise a pickingcontroller 612 configured to control operational functions of thepicking attachment 602. In which case, the user interface 632 of thehand-held drive unit 600 would comprise picking attachment controloperators 622, and the picking controller 612 would be responsive tooperational commands generated with the picking attachment controloperators 622.

The vehicular controller(s) may additionally comprise a carriagecontroller 621 configured to control operational functions of thecarriage control unit 611, which is configured to control the forkcarriage assembly 206. In which case, the user interface 632 of thehand-held drive unit 600 would comprise carriage control operators 631,and the carriage controller 621 would be responsive to operationalcommands generated with the carriage control operators 631.

The materials handling vehicle 102 may further comprise a camera 212coupled to the fork carriage assembly 206, with the camera 212 beingconfigured to send image data representing objects within a field ofview of the camera 212 to the hand-held drive unit 600. The hand-helddrive unit 600 may comprise a touch screen display 634 or other type ofdisplay for displaying image data representing objects within the fieldof view of the camera 212. In this manner, a ground-based operator canuse the image data as an aide to using the hand-held drive unit 600 tocontrol various functions of the materials handling vehicle 102. This isparticularly advantageous where the field of view of the camera 212extends beyond the field of view of an operator sharing a vehicletransit surface 106 with the materials handling vehicle 102. In someembodiments, the hand-held drive unit 600 may be configured to allow anoperator to view images of the picking attachment 602 and sendoperational commands to the picking controller 612 through pickingattachment control operators 622 of the hand-held drive unit 600 tocontrol operational functions of the picking attachment 602.

It is also contemplated that the hand-held drive unit 600 may beconfigured to control the field of view of the camera 212. For example,the field of view of the camera 212 may be controlled by changing theposition or orientation of the camera 212, by controlling the zoom ofthe camera optics, by controlling an aiming direction of the cameraoptics, or combinations thereof. In various embodiments, the hand-helddrive unit 600 is configured to control focusing optics of the camera212. In other embodiments, the camera 212 may be coupled to the forkcarriage assembly 206 by a camera positioner 214, and the hand-helddrive unit 600 may be configured to control the operational functions ofthe camera positioner 214.

It is also contemplated that the camera 212 may be coupled to the forkcarriage assembly 206 either internally or externally. Aninternally-coupled camera could reside at least partially within thefork carriage assembly 206, such as with a pinhole camera. Anexternally-coupled camera may be attached to the fork carriage assembly206 by any suitable means, such as with coupling mechanisms (screws,bolts, etc.), attachment mechanisms (camera base-mounts, brackets,etc.), adhesives, or combinations thereof.

In many cases, it will be advantageous to ensure that the hand-helddrive unit 600 is secured to a surface of the vehicle body 104 that isnot located within a path of vertical movement of the fork carriageassembly 206. In this manner, by ensuring that the drive unit 600 isaccessible from the power unit side 204, and not the fork side 202 ofthe materials handling vehicle 102, the operator will not be required towalk under the fork carriage assembly 206 to access the hand-held driveunit 600. In some embodiments, it may be sufficient to merely ensurethat the hand-held drive unit 600 is secured to a surface of the vehiclebody 104 that is not located at the fork side 202 of the vehicle body104. In other embodiments, it may be advantageous to ensure that thehand-held drive unit 600 is held within a drive unit case 638, and thedrive unit case 638 is secured to the vehicle body 104. For example,referring to FIG. 2, the materials handling vehicle 102 includes thedrive unit case 638 housing the hand-held drive unit 600 at the powerunit side 204 of the materials handling vehicle 102.

It is contemplated that the hand-held drive unit 600 described above maybe secured to the materials handling vehicle 102, or may be present at alocation remote from the materials handling vehicle 102. Further, thefunctionality of the hand-held drive unit 600 may be presented morebroadly in the form of a remote controller that is communicativelycoupled to the materials handling vehicle 102 through, for example, awireless communication link. The remote controller may or may not be ahand-held and may or may not be secured to the materials handlingvehicle 102. The remote controller may comprise a video link to displayimage data from the camera 212. Contemplated remote controllers may, forexample, be presented as a desktop computer, a laptop computer, asmartphone, a tablet, a wearable computing device, or some combinationthereof. It is also contemplated that the remote controller, whetherhand-held or not, may be utilized in a dual mode operation where usercontrol is facilitated from two separate remote controllers. Forexample, and not by way of limitation, in one type of dual modeoperation, a user is able to control vehicular operations through aremote controller at a remote location, such as through a laptopcomputer, while also permitting the same or another user to sign inthrough a secured webpage or a software application loaded on asmartphone, or other hand-held device, to control such vehicularoperations. Regardless of the mode of operation, it is contemplated thatthe remote controller may be utilized by an operator at a location thatis remote from the materials handling vehicle 102, or by an operatorsharing the vehicle transit surface 106 with the materials handlingvehicle 102.

Referring to FIG. 12, a block diagram illustrates a computing device700, through which embodiments of the disclosure can be implemented. Thecomputing device 700 described herein is but one example of a suitablecomputing device and does not suggest any limitation on the scope of anyembodiments presented. For example, the computing device 700 in someembodiments is an example of the remote controller such as the hand-helddrive unit 600 described herein and/or other suitable mobile clientdevices that may be communicatively coupled to the hand-held drive unit600. The computing device 700 may be communicatively coupled to one ormore computing devices through a warehouse management system. Nothingillustrated or described with respect to the computing device 700 shouldbe interpreted as being required or as creating any type of dependencywith respect to any element or plurality of elements. In variousembodiments, a computing device 700 may include, but need not be limitedto, a desktop, laptop, server, client, tablet, smartphone, or any othertype of device that can compress data. In an embodiment, the computingdevice 700 includes at least one processor 702 and memory (non-volatilememory 708 and/or volatile memory 710). In embodiments, the one or moretarget TOF depth maps 28 and/or one or more warehouse maps 30 describedherein may be stored in the memory. The computing device 700 can includeone or more displays (such as the touch screen display 634 of thehand-hand drive unit 600) and/or output devices 704 such as monitors,speakers, headphones, projectors, wearable-displays, holographicdisplays, and/or printers, for example. Output devices 704 may beconfigured to output audio, visual, and/or tactile signals and mayfurther include, for example, audio speakers, devices that emit energy(radio, microwave, infrared, visible light, ultraviolet, x-ray and gammaray), electronic output devices (Wi-Fi, radar, laser, etc.), audio (ofany frequency), etc.

The computing device 700 may further include one or more input devices706 which can include, by way of example, any type of mouse, keyboard,disk/media drive, memory stick/thumb-drive, memory card, pen,touch-input device, biometric scanner, voice/auditory input device,motion-detector, camera, scale, and the like. Input devices 706 mayfurther include sensors, such as biometric (voice, facial-recognition,iris or other types of eye recognition, hand geometry, fingerprint, DNA,or any other suitable type of biometric data, etc.), video/still images,motion data (accelerometer, GPS, magnetometer, gyroscope, etc.) andaudio (including ultrasonic sound waves). Input devices 706 may furtherinclude cameras (with or without audio recording), such as digitaland/or analog cameras, still cameras, video cameras, thermal imagingcameras, infrared cameras, cameras with a charge-couple display,night-vision cameras, three-dimensional cameras, webcams, audiorecorders, and the like. For example, an input device 706 may includethe camera 212 described herein.

The computing device 700 typically includes non-volatile memory 708(ROM, flash memory, etc.), volatile memory 710 (RAM, etc.), or acombination thereof. A network interface 712 can facilitatecommunications over a network 714 via wires, via a wide area network,via a local area network, via a personal area network, via a cellularnetwork, via a satellite network, etc. Suitable local area networks mayinclude wired Ethernet and/or wireless technologies such as, forexample, wireless fidelity (Wi-Fi). Suitable personal area networks mayinclude wireless technologies such as, for example, IrDA, Bluetooth,Wireless USB, Z-Wave, ZigBee, and/or other near field communicationprotocols. Suitable personal area networks may similarly include wiredcomputer buses such as, for example, USB and FireWire. Suitable cellularnetworks include, but are not limited to, technologies such as LTE,WiMAX, UMTS, CDMA, and GSM. Network interface 712 can be communicativelycoupled to any device capable of transmitting and/or receiving data viathe network 714. Accordingly, the network interface hardware 712 caninclude a communication transceiver for sending and/or receiving anywired or wireless communication. For example, the network interfacehardware 712 may include an antenna, a modem, LAN port, Wi-Fi card,WiMax card, mobile communications hardware, near-field communicationhardware, satellite communication hardware and/or any wired or wirelesshardware for communicating with other networks and/or devices.

A computer-readable medium 716 may comprise a plurality of computerreadable mediums, each of which may be either a computer readablestorage medium or a computer readable signal medium. A computer readablestorage medium 716 may be non-transitory in that it excludes anytransitory, propagating signal as a storage medium and may reside, forexample, within an input device 706, non-volatile memory 708, volatilememory 710, or any combination thereof. A computer readable storagemedium can include tangible media that is able to store instructionsassociated with, or used by, a device or system. A computer readablestorage medium includes, by way of example: RAM, ROM, cache, fiberoptics, EPROM/Flash memory, CD/DVD/BD-ROM, hard disk drives, solid-statestorage, optical or magnetic storage devices, diskettes, electricalconnections having a wire, or any combination thereof. A computerreadable storage medium may also include, for example, a system ordevice that is of a magnetic, optical, semiconductor, or electronictype. Computer readable storage media and computer readable signal mediaare mutually exclusive.

A computer readable signal medium can include any type of computerreadable medium that is not a computer readable storage medium and mayinclude, for example, propagated signals taking any number of forms suchas optical, electromagnetic, or a combination thereof. A computerreadable signal medium may include propagated data signals containingcomputer readable code, for example, within a carrier wave. Computerreadable storage media and computer readable signal media are mutuallyexclusive.

The computing device 700 may include one or more network interfaces 712to facilitate communication with one or more remote devices, which mayinclude, for example, client and/or server devices. A network interface712 may also be described as a communications module, as these terms maybe used interchangeably. For clarity, it is noted that usage of the term“in communication with” herein, with respect to the FIG. 12, orelsewhere, may refer to one-way communication or two-way communication.

It is contemplated that the present disclosure enables an existingworkspace designed for palletized loads to be retrofitted to increasepicking density of the existing shelving with the shelf insert 404 orrack module 34 and the addition of the picking attachment 602 to thematerials handling vehicle 102 which may be, for example, a forklift.For example, the shelf insert 404 may be a retrofit of palletizedshelving. Controllers and semi-autonomous/and/or autonomous hardwareenables such retrofitted equipment to pick and place totes 51 or otherobjects automatically without a need to procure specific robotic pickand place equipment and storage units.

It is contemplated that the goods storage and retrieval systems 10described herein may be integrated with a variety of additional hardwareto build a complete goods-to-man warehousing system. This additionalhardware may, for example, comprise conventional, or yet-to-bedeveloped, pick station hardware, transit hardware for mobile storagecarts, cart loading station hardware, or any other warehouse hardwarefacilitating the integration of the goods storage and retrieval systems10 described herein into a complete goods-to-man warehousing system. Forexample, FIG. 16 illustrates a goods-to-man warehousing systemcomprising: materials handling vehicles 102 and a multilevel warehouseracking system 12 configured as described above; additional warehouseaisles for accommodating the transit of AGV-enabled tugger trains 108,which may be loaded with mobile storage carts 14; a staging area 105 forAGV-enabled tugger trains; a battery charging station to which materialshandling vehicles 102 may traverse; and two goods-to-man pick stations110 configured to feed empty totes to an operator at the pick stationfor the transfer of goods picked from mobile storage carts 14 to a putwall for order consolidation. In operation, the materials handlingvehicles transfer mobile storage carts 14 to the tugger trains 108 atone or more designated pick and delivery (P&D) stations 109, whichstations may function as the cart home position 16 described above. TheAGV-enabled tugger trains 108 subsequently transfer the mobile storagecarts 14 to the goods-to-man pick stations 110 for order picking andconsolidation.

It is contemplated that the materials handling vehicles 102 may operateautonomously in a user restricted area in individual aisles and thatthere may be only one vehicle per aisle. Alternatively, a singlematerials handling vehicle 102 may traverse between different aisles. Itis also contemplated that the materials handling vehicles 102 may becommunicatively coupled to a warehouse management system (WMS), or otherlogistics system, such that the vehicle is given locations along eachaisle to pick or place articles in warehouse racks on either side of theaisle. For example, to pick articles to fill a pick cart, it iscontemplated that a materials handling vehicle 102 may couple with amobile storage cart 14 at the P&D station 109, or another type ofdesignated cart home position, as described above. The vehicle 102 willtraverse individual aisles until either the cart 14 is filled, or theWMS indicates that no other articles are required. The vehicle 102 willthen place the cart 14 in the P&D station 109 for pick-up by a tuggertrain 108. Alternatively, the vehicle 102 may position the cart 14 suchthat it is coupled to the tugger train 108. In either case, the tuggertrain 108 then transports the cart 14 to a goods-to-man pick station 110where either a user or another article manipulator will retrievearticles from the cart 14 to fill individual totes for packaging andshipping.

To place articles in the racks of the multilevel warehouse rackingsystem 12, along the aisles, a mobile storage cart 14 is filled witharticles at a goods-to-man pick station 110. A tugger train 108 thenretrieves the mobile storage cart 14 and transports it to the P&Dstation 109. A materials handling vehicle 102 couples with the cart 14and proceeds to transfer articles from the cart 14 to pick locations inthe warehouse racks. Empty carts 14 can be placed in the P&D station 109for transport to a storage area by a tugger train 108, or can be left onthe materials handling vehicle for future article picking. It is alsocontemplated that a mobile storage cart 14 may be passed betweenvehicles 102 within a P&D station 109 such that multiple vehicles 102are used to fill and/or empty a cart 14 among multiple aisles. It iscontemplated that the mobile storage carts 14 may comprise locationindicia such that a vision system and/or user at the goods to manstation can place/pick an article in the proper location and maintainthe integrity of WMS data.

FIG. 17, which uses the same reference numbers as FIG. 16 to illustratelike components, illustrates a goods-to-man warehousing system with adifferent pick station configuration and a cart loading station defininga different type of cart home position 16, i.e., a cart home position 16that is removed from the P&D station 109. The pick station configurationof FIG. 17 is similar to that of FIG. 16 in that it includes twogoods-to-man pick stations 110, but it also includes a goods-to-manreplenish station 107, which allows an operator to provide goods forreplenishing stock in the multilevel warehouse racking system 12.

FIG. 18 illustrates a process for integration and utilization with thegoods-to-man warehousing systems of FIG. 16 and/or FIG. 17. Inparticular, FIG. 18 illustrates a process of exchanging one or moremobile storage carts 14 between at least two of a storage area, ashipping area, and a loading area. Such mobile storage cart(s) 14 may beengaged with a materials handling vehicle 102 or coupled to the tuggertrain 108 as described herein. With respect to an exchange between thestorage area at the top of FIG. 18, which is part of a restricted area,and the loading area, an empty mobile storage cart may proceed to exitthe storage area through an empty cart out buffer. The empty mobilestorage cart, i.e., an “empty” cart, may then travel along a path tocross an empty cart in loading buffer to enter the loading area. In theloading area, the empty cart may be loaded while moving between one ormore zones in a goods-to-man station 110. It is contemplated that anempty cart may be loaded with articles for multiple orders in, forexample, the loading area such that a single cycle through thegoods-to-man station 110 will load the empty cart and increase systemefficiency by reducing a number of carts transitioning through thesystem within the process. Thus, the empty cart is loaded with one ormore objects to become a partially full or full cart, i.e., a “loaded”cart, which proceeds out of the loading area through a full cart outloading buffer. In an exchange between the loading area and the storagearea, the loaded cart travels along a path crossing a full cart of putsto restricted area put buffer to be received in a full cart in putbuffer in the storage area.

One or more materials handling vehicles 102 may cooperate with the fullcart with respect to put and place operations as described herein. Forexample, an inventory exchange may occur between objects from thearriving loaded cart with objects (such as totes) stored within one ormore very narrow aisles or regular aisles that the materials handlingvehicle(s) 102 travel between. In an exchange between the storage areaand the shipping area, the previously loaded cart, or a newly loadedcart post such an inventory exchange, may then exit the storage areathrough the full cart out pick buffer to travel along a path crossingthe full cart of picks to shipping buffer for entry into the full cartin shipping buffer in the shipping area. In the shipping area, theloaded cart may be emptied at, for example, another goods-to-man station110. It is contemplated that the loaded cart may be loaded with articlesfor multiple orders such that a single cycle through the goods-to-manstation 110 will empty the loaded cart and increase system efficiency byreducing the number of carts transitioning through the system within theprocess. The items emptied from the cart(s) may then be prepared forshipping and delivery.

In an exchange between the shipping area and the storage area, theemptied cart may exist the shipping area through an empty cart outshipping buffer to travel along a path that crosses a restricted areaempty in buffer and enters the storage area (i.e., the restricted area)through an empty cart in buffer. The emptied cart may then travelthrough the restricted area to participate in pick and put operations asdescribed herein or may exist the storage area through the empty cartout buffer as described above to be loaded in the loading area.

Alternatively, in an exchange between the shipping area and the loadingarea, the emptied cart may exist the shipping area through an empty cartout shipping buffer to travel along a path that crosses the empty cartin loading buffer to arrive back through the empty cart in loadingbuffer at the loading area to repeat one or more steps of the process asdescribed above. The steps of this process are not restricted to theorder described above and may occur to exchange goods and carts betweenat least two of the areas. In embodiments, one or more of thegoods-to-man load station(s) and the goods-to-man shipping station(s)may be identical.

Further, a materials handling vehicle 102 engaged with a mobile storagecart 14 may be positioned at a staging area 105 and may travel from thestaging area 105 to a battery exchange area in order to change a batteryat a battery changing station. Similarly, a materials handling vehicle102 engaged with a mobile storage cart 14 in the restricted area maytravel to the battery exchange area.

For the purposes of describing and defining the present invention, it isnoted that reference herein to a characteristic of the subject matter ofthe present disclosure being “based on” a parameter, variable, or othercharacteristic is not intended to denote that the characteristic isexclusively based on the listed parameter, variable, or characteristic.Rather, reference herein to a characteristic that is a “based” on alisted parameter, variable, etc., is intended to be open ended such thatthe characteristic may be based on a single parameter, variable, etc.,or a plurality of parameters, variables, etc.

It is also noted that recitations herein of “at least one” or “one ormore” components, elements, etc., should not be used to create aninference that the alternative use of the articles “a” or “an” should belimited to a single component, element, etc.

It is noted that recitations herein of a component of the presentdisclosure being “configured” in a particular way, to embody aparticular property, or to function in a particular manner, arestructural recitations, as opposed to recitations of intended use. Morespecifically, the references herein to the manner in which a componentis “configured” denotes an existing physical condition of the componentand, as such, is to be taken as a definite recitation of the structuralcharacteristics of the component.

Having described the subject matter of the present disclosure in detailand by reference to specific embodiments thereof, it is noted that thevarious details disclosed herein should not be taken to imply that thesedetails relate to elements that are essential components of the variousembodiments described herein, even in cases where a particular elementis illustrated in each of the drawings that accompany the presentdescription. Further, it will be apparent that modifications andvariations are possible without departing from the scope of the presentdisclosure, including, but not limited to, embodiments defined in theappended claims. More specifically, although some aspects of the presentdisclosure are identified herein as preferred or particularlyadvantageous, it is contemplated that the present disclosure is notnecessarily limited to these aspects.

It is noted that one or more of the following claims utilize the term“wherein” as a transitional phrase. For the purposes of defining thepresent invention, it is noted that this term is introduced in theclaims as an open-ended transitional phrase that is used to introduce arecitation of a series of characteristics of the structure and should beinterpreted in like manner as the more commonly used open-ended preambleterm “comprising.”

What is claimed is:
 1. A goods storage and retrieval system, comprisinga multilevel warehouse racking system, a mobile storage cart, a carthome position, and a materials handling vehicle disposed on a vehicletransit surface, wherein: the materials handling vehicle comprises avehicle body, a plurality of wheels supporting the vehicle body, atraction control unit, a braking system, and a steering assembly, eachoperatively coupled to one or more of the vehicle wheels, a mastassembly, a fork carriage assembly movably coupled to the mast assembly,a mast assembly control unit, a carriage control unit, a pickingattachment secured to the fork carriage assembly, a cart engagementsubsystem, a navigation subsystem, and one or more vehicular controllersin communication with the traction control unit, the braking system, thesteering assembly, the mast assembly control unit, the carriage controlunit, the picking attachment, the cart engagement subsystem, and thenavigation subsystem; the cart engagement subsystem is characterized bya cart engagement field of view; the one or more vehicular controllersof the materials handling vehicle executes vehicle functions to: (i) usethe navigation subsystem to navigate the materials handling vehiclealong the vehicle transit surface to a localized engagement positionwhere the cart home position is within the cart engagement field ofview; and (ii) use the cart engagement subsystem to engage the mobilestorage cart in the cart home position with the fork carriage assembly.2. The goods storage and retrieval system as claimed in claim 1 wherein:the cart engagement subsystem is further characterized by a closeapproach field of view that is more restricted than the cart engagementfield of view; and the cart engagement subsystem transitions from aninitial approach mode in the cart engagement field of view to a closeapproach mode in the close approach field of view as the cart homeposition moves into the close approach field of view.
 3. The goodsstorage and retrieval system as claimed in claim 2 wherein: the cartengagement subsystem comprises a time-of-flight (TOF) systemcharacterized by the close approach field of view; the close approachmode relies primarily on the TOF system as the cart home position movesinto the close approach field of view; the cart engagement subsystem isconfigured to generate a target TOF depth map of the mobile storagecart; and the one or more vehicular controllers of the materialshandling vehicle executes vehicle functions to (i) use the cartengagement subsystem to generate the target TOF depth map of the mobilestorage cart in the cart home position, and (ii) use the cart engagementsubsystem to determine a range position of the mobile storage cart withrespect to the cart engagement subsystem based on the target TOF depthmap.
 4. The goods storage and retrieval system as claimed in claim 1wherein: the cart engagement subsystem comprises a vision system and atime-of-flight (TOF) system; the cart engagement subsystem is furthercharacterized by a close approach field of view that is more restrictedthan the cart engagement field of view; and the cart engagement field ofview is defined by the vision system.
 5. The goods storage and retrievalsystem as claimed in claim 4 wherein: the close approach field of viewis defined by the TOF system; and the cart engagement subsystemtransitions from cart engagement operations that rely primarily on thevision system to cart engagement operations that rely primarily on theTOF system as the cart home position moves into the close approach fieldof view.
 6. The goods storage and retrieval system as claimed in claim 1wherein the cart engagement subsystem is operatively coupled to at leastone of the traction control unit, the braking system, the steeringassembly, the mast assembly control unit, the carriage control unit, andthe picking attachment to facilitate cart engagement.
 7. The goodsstorage and retrieval system as claimed in claim 1 wherein: thenavigation subsystem comprises one or more environmental sensors and anenvironmental database; the environmental sensors are configured tocapture data indicative of a position of the materials handling vehiclerelative to the multilevel warehouse racking system, the vehicle transitsurface, or both; the environmental database comprises stored dataindicative of the multilevel warehouse racking system, the vehicletransit surface, or both; and the navigation subsystem is configured toenable at least partially automated navigation of the materials handlingvehicle along the vehicle transit surface utilizing the captured dataand the stored data.
 8. The goods storage and retrieval system asclaimed in claim 1 wherein the navigation subsystem is operativelycoupled to at least one of the traction control unit, the brakingsystem, the steering assembly, the mast assembly control unit, thecarriage control unit, and the picking attachment to facilitate cartengagement.
 9. The goods storage and retrieval system as claimed inclaim 1 wherein: a warehouse map is stored in a memory communicativelycoupled to the one or more vehicular controllers; and the one or morevehicular controllers of the materials handling vehicle executes vehiclefunctions to (i) use the navigation subsystem to determine a localizedposition of the materials handling vehicle with respect to the vehicletransit surface of a warehouse based on a position of the materialshandling vehicle in the warehouse in comparison with the warehouse map,and (ii) use the navigation system to track navigation of the materialshandling vehicle along the vehicle transit surface based on thelocalized position, navigate the materials handling vehicle along thevehicle transit surface in at least a partially automated manner, orboth.
 10. The goods storage and retrieval system as claimed in claim 1wherein the picking attachment comprises an X-Y-Z-Ψ positioner and theone or more vehicular controllers of the materials handling vehicleexecutes vehicle functions to use the X-Y-Z-Ψ positioner of the pickingattachment to engage and disengage a target tote positioned in themultilevel warehouse racking system with the picking attachment.
 11. Thegoods storage and retrieval system as claimed in claim 1 wherein: thematerials handling vehicle further comprises a picking attachmentsubsystem comprising the picking attachment and a time-of-flight (TOF)system; the picking attachment comprises an X-Y-Z-Ψ positioner; thepicking attachment subsystem is configured to generate a target TOFdepth map of a target tote; the one or more vehicular controllers of thematerials handling vehicle executes vehicle functions to use the X-Y-Z-Ψpositioner of the picking attachment subsystem to engage the target totewith the picking attachment based on the target TOF depth map.
 12. Thegoods storage and retrieval system as claimed in claim 11 wherein thenavigation subsystem is configured to position the materials handlingvehicle such that the target tote is within a tote engagement field ofview of the TOF system.
 13. The goods storage and retrieval system asclaimed in claim 11 wherein: the navigation subsystem comprises a visionsystem; the multilevel warehouse racking system comprises a targetfiducial associated with the target tote; and the navigation subsystemis configured to position the materials handling vehicle such that thetarget fiducial is within a field of view of the vision system.
 14. Thegoods storage and retrieval system as claimed in claim 13 wherein thenavigation subsystem is configured to utilize the target fiducial toposition the materials handling vehicle such that the target tote iswithin a tote engagement field of view of the TOF system.
 15. The goodsstorage and retrieval system as claimed in claim 11 wherein the X-Y-Z-Ψpositioner comprises an X-positioner configured to move the pickingattachment in a first degree of freedom along a first lateral axis in alateral plane, a Y-positioner configured to move the picking attachmentin a second degree of freedom along a second lateral axis perpendicularto the first lateral axis in the lateral plane, a Z-positionerconfigured to move the picking attachment in a third degree of freedomalong a Z-axis perpendicular to the first lateral axis and the secondlateral axis, and a rotational Ψ-positioner configured to rotate thepicking attachment in a fourth degree of freedom about the Z-axis.
 16. Agoods storage and retrieval system, comprising a multilevel warehouseracking system, a mobile storage cart, a cart home position, and amaterials handling vehicle disposed on a vehicle transit surface,wherein: the materials handling vehicle comprises a vehicle body, a forkcarriage assembly, a carriage control unit, a picking attachment securedto the fork carriage assembly, a cart engagement subsystem, a navigationsubsystem, and one or more vehicular controllers in communication withthe carriage control unit, the picking attachment, the cart engagementsubsystem, and the navigation subsystem; the cart engagement subsystemis characterized by a cart engagement field of view; the one or morevehicular controllers of the materials handling vehicle executes vehiclefunctions to: (i) use the navigation subsystem to navigate the materialshandling vehicle along the vehicle transit surface to a localizedengagement position where the cart home position is within the cartengagement field of view; and (ii) use the cart engagement subsystem toengage the mobile storage cart in the cart home position with the forkcarriage assembly.
 17. The goods storage and retrieval system as claimedin claim 16 wherein the materials handling vehicle further comprises: aplurality of wheels supporting the vehicle body, a traction controlunit, a braking system, and a steering assembly, each operativelycoupled to one or more of the vehicle wheels, a mast assembly, and amast assembly control unit; and the one or more vehicular controllersare in communication with the traction control unit, the braking system,the steering assembly, and the mast assembly control unit.
 18. The goodsstorage and retrieval system as claimed in claim 17 wherein through theone or more vehicle controllers: the cart engagement subsystem isoperatively coupled to at least one of the traction control unit, thebraking system, the steering assembly, the mast assembly control unit,the carriage control unit, and the picking attachment to facilitate cartengagement.
 19. The goods storage and retrieval system as claimed inclaim 17 wherein through the one or more vehicle controllers: thenavigation subsystem is operatively coupled to at least one of thetraction control unit, the braking system, the steering assembly, themast assembly control unit, the carriage control unit, and the pickingattachment to facilitate cart engagement.
 20. The goods storage andretrieval system as claimed in claim 16 wherein: the navigationsubsystem is operatively coupled to at least one of the carriage controlunit and the picking attachment to facilitate cart engagement.
 21. Amaterials handling vehicle configured to navigate a vehicle transitsurface, the materials handling vehicle comprising: a vehicle body, aplurality of wheels supporting the vehicle body, a traction controlunit, a braking system, and a steering assembly, each operativelycoupled to one or more of the vehicle wheels, a mast assembly, a forkcarriage assembly movably coupled to the mast assembly, a mast assemblycontrol unit, a carriage control unit, a picking attachment secured tothe fork carriage assembly, a cart engagement subsystem, a navigationsubsystem, and one or more vehicular controllers in communication withthe traction control unit, the braking system, the steering assembly,the mast assembly control unit, the carriage control unit, the pickingattachment, the cart engagement subsystem, and the navigation subsystem,wherein the cart engagement subsystem is characterized by a cartengagement field of view; and the one or more vehicular controllers ofthe materials handling vehicle executes vehicle functions to: (i) usethe navigation subsystem to navigate the materials handling vehiclealong the vehicle transit surface to a localized engagement positionwhere a cart home position is within the cart engagement field of view;and (ii) use the cart engagement subsystem to engage a mobile storagecart in the cart home position with the fork carriage assembly.
 22. Amethod of operating a goods storage and retrieval system, the methodcomprising: providing the goods storage and retrieval system comprisinga multilevel warehouse racking system, a mobile storage cart, a carthome position, and a materials handling vehicle disposed on a vehicletransit surface, wherein: the materials handling vehicle comprises avehicle body, a plurality of wheels supporting the vehicle body, atraction control unit, a braking system, and a steering assembly, eachoperatively coupled to one or more of the vehicle wheels, a mastassembly, a fork carriage assembly movably coupled to the mast assembly,a mast assembly control unit, a carriage control unit, a pickingattachment secured to the fork carriage assembly, a cart engagementsubsystem, a navigation subsystem, and one or more vehicular controllersin communication with the traction control unit, the braking system, thesteering assembly, the mast assembly control unit, the carriage controlunit, the picking attachment, the cart engagement subsystem, and thenavigation subsystem; and the cart engagement subsystem is characterizedby a cart engagement field of view; navigating the materials handlingvehicle along the vehicle transit surface to a localized engagementposition where the cart home position is within the cart engagementfield of view through use of the navigation subsystem and the one ormore vehicular controllers; and engaging the mobile storage cart in thecart home position with the fork carriage assembly through use of thecart engagement subsystem.
 23. The method as claimed in claim 22 furthercomprising: engaging or disengaging a target tote positioned in themobile storage cart or the multilevel warehouse racking system with thepicking attachment secured to the fork carriage assembly and comprisingan X-Y-Z-Ψ positioner through use of the X-Y-Z-Ψ positioner.
 24. Themethod as claimed in claim 22 further comprising: assigning a velocitynumber to a stock keeping unit (SKU) associated with a target tote inthe multilevel warehouse racking system based on an order velocityindicative of a frequency of usage parameter associated with the targettote.
 25. The method as claimed in claim 24 further comprising:associating a relatively high velocity number with a low storageposition on a low shelf of the multilevel warehouse racking system; andassociating a relatively low velocity number with a high storageposition on a high shelf of the multilevel warehouse racking system. 26.The method as claimed in claim 24 further comprising: using the pickingattachment and the fork carriage assembly to move the target tote from aportion of the multilevel warehouse racking system associated with arelatively low velocity number to a portion of the multilevel warehouseracking system associated with a relatively high velocity number basedon an increase in the order velocity with respect to the target tote.27. The method as claimed in claim 24 further comprising: using thepicking attachment and the fork carriage assembly to move the targettote from a portion of the multilevel warehouse racking systemassociated with a relatively high velocity number to a portion of themultilevel warehouse racking system associated with a relatively lowvelocity number based on a decrease in the order velocity with respectto the target tote.
 28. The method as claimed in claim 24 furthercomprising: engaging a first target tote at a first storage position ona high shelf associated with a relatively low velocity number with thepicking attachment; and placing with the picking attachment the firsttarget tote in the mobile storage cart engaged by the fork carriageassembly.
 29. The method as claimed in claim 28 further comprising:navigating the materials handling vehicle to a second target tote whenthe second target tote is assigned a relatively high velocity number andis within a close distance to the first storage position; engaging thesecond target tote with the picking attachment; and lowering the secondtarget tote to a low shelf associated with the relatively high velocitynumber or placing the second target tote in the mobile storage cart withthe picking attachment.
 30. The method as claimed in claim 29 furthercomprising: navigating the materials handling vehicle to a subsequentpick location when the second target tote is placed in the mobilestorage cart; and placing the second target tote on the low shelfassociated with the relatively high velocity number while at thesubsequent pick location.
 31. The method as claimed in claim 24 furthercomprising: engaging a first target tote at a first storage position ona low shelf associated with a relatively high velocity number with thepicking attachment; and placing with the picking attachment the firsttarget tote in the mobile storage cart engaged by the fork carriageassembly.
 32. The method as claimed in claim 31 further comprising:navigating the materials handling vehicle to a second target tote whenthe second target tote is assigned a relatively low velocity number andis within a close distance to the first storage position on the lowshelf; engaging the second target tote with the picking attachment; andraising the second target tote to a high shelf associated with therelatively low velocity number or placing the second target tote in themobile storage cart with the picking attachment.
 33. The method asclaimed in claim 32 further comprising: navigating the materialshandling vehicle to a subsequent pick location when the second targettote is placed in the mobile storage cart; and placing the second targettote on the high shelf associated with the relatively low velocitynumber while at the subsequent pick location.
 34. The method as claimedin claim 22 further comprising: positioning the materials handlingvehicle in a first aisle of the multilevel warehouse racking system;placing with the picking attachment one or more target totes in themobile storage cart engaged by the fork carriage assembly; and using themobile storage cart as a temporary storage location to level inventorywhen one or more inventory orders are received such that the one or moretarget totes are shuffled between the mobile storage cart and aplurality of shelves of the multilevel warehouse racking system based ona respective order velocity indicative of a frequency of usage parameterassociated with each target tote to optimize a usage parameter withrespect to the first aisle.
 35. The method as claimed in claim 34further comprising: assigning a relatively low velocity numberassociated with a high shelf of the multilevel warehouse racking systemto a SKU associated with a first target tote; storing the first targettote in the mobile storage cart; assigning a relatively high velocitynumber associated with a low shelf of the multilevel warehouse rackingsystem to a SKU associated with a second target tote; receivinginformation indicative of the second target tote being stored on a highshelf of the multilevel warehouse racking system; navigating thematerials handling vehicle to a location of the multilevel warehouseracking system associated with the high shelf during an off-peak pickingtime or an off shift time; moving the mobile storage cart engaged by thefork carriage assembly to the high shelf; exchanging with the pickingattachment the first target tote stored in the mobile storage cart withthe second target tote stored on the high shelf to store the secondtarget tote in the mobile storage cart.
 36. The method as claimed inclaim 22 further comprising: placing with the picking attachment one ormore target totes in the mobile storage cart engaged by the forkcarriage assembly such that the mobile storage cart is utilized as atemporary storage location; interleaving picking attachment pick andplace operations by picking up and placing away multiple target totesduring a single trip of the materials handling vehicle down an aisle ofthe multilevel warehouse racking system.
 37. The method as claimed inclaim 36 further comprising: storing a first target tote on a shelf of aplurality of shelves in a first aisle of the multilevel warehouseracking system; storing a second target tote in the mobile storage cart;engaging the first target tote on the shelf in a shelf location to pickup the first target tote with the picking attachment; removing the firsttarget tote from the shelf location with the picking attachment; placingthe first target tote on a shelf of the mobile storage cart with thepicking attachment; engaging the second target tote stored in the mobilestorage cart with the picking attachment; removing the second targettote from the mobile storage cart with the picking attachment; andplacing the second target tote in the shelf location to place away thesecond target tote with the picking attachment.